This invention has to do with material handling equipment specifically with palletizer equipment having multi-axis hands carried on a boom, the boom carried on a mast for vertical movement while the hand is carried on the boom for transverse movement. Such palletizers and depalletizers are well known n the industry and are widely used in automated plants wherein palletized products, typically in cartons, are sent or received by a manufacturing or packaging plant.
A typical sequence in the operation of a palletizer would involve the steps of the palletizer receiving a plurality of cartons from a particular work station; picking up a row of these cartons through the use of a boom mounted clamp hand, transporting the row of cartons to a pallet state, depositing the cartons on the pallet, the returning of the clamp hand to the input conveyor for a second row of cartons, transporting those cartons to the pallet location and locating those cartons adjacent the previously deposited row of cartons on the pallet. This process wold be repeated until a layer of cartons were accumulated the pallet. Such a layer of cartons might typically be composed of three rows of cartons ad would have therefore required three "pick and place" trips by the clamp hand to construct a single layer of cartons on the pallet.
It is also known that a palletizer, with a specific clamp hand configuration can pick up more than a single row of cartons, even with the cartons arranged nonuniformly.
In another situation it has been found that it is advantageous to use a palletizer to depalletize a palletized load of product. In the depalletizing situation the product is taken off the top layer of a palletized load and transported to a take-away or other process related conveyor. This would be an appropriate material handling step or stage in, for instance, a bottling plant where cartons of empty bottles are delivered to the plant on a pallet and these cartons are then subsequently depalletized onto a conveyor leading to bottle washers, fillers, cappers, labelers and recartoners. In a typical environment; a pallet of cartons containing empty bottles, such a palletized load being upwards of nine feet tall, would be delivered to the bottling plant. At the plant a crew would be assigned to manually destack or depalletize the load of bottles and cartons by taking cartons off the top of the pallet and putting them on a take-away conveyor. As these pallets may be relatively tall, as stated above. nine feet tall it is often necessary to utilize a scaffolding system or ladder system to give the unloading person access to the upper layers of the pallet. The instant invention is designed to eliminate the manual depalletizing of cartons of product. An increase in productivity can be realized through the use of a layer clamp hand having the capability of depalletizing a pallet layer-by-layer.
The advantages of the invention presented herein will be readily apparent from a careful reading of the following specification in conjunction with an understanding of the figures presented herein.